Does the coolant in the reservoir ever circulate through the cooling system? Not a surge tank setup, but a radiator with cap and overflow hose that goes into a separate reservoir. Similar to this picture.
^This.yes
Every time the coolant temp rises, some fluid gets pushed into the overflow tank and any time the engine cools down, a similar amount gets sucked back in.
Not in OP's example.Yes, you can check the cap on the coolant tank. It will be a sealed cap capable of taking pressure. Coolant circulates through it. It’s more than just taking the expansion fluid.
Maybe he just wants to add distilled water to replenish (that which has evaporated) and would like the juice in the the bottle to have anti-freeze properties by the time Winter blows in.Not in OP's example.
What's the backstory, does OP want to do a "gentle" coolant changeout? Fix a concentration issue to get back to 50/50? Working only with the overflow bottle is a dumb way to maybe eventually get there.
What Year Model car and engine?Does the coolant in the reservoir ever circulate through the cooling system? Not a surge tank setup, but a radiator with cap and overflow hose that goes into a separate reservoir. Similar to this picture.
photo removed
I was curious after reading a bottle of Hy-per Cool Super Coolant. I have witnessed after doing cooling system work, that the system will pull some coolant from the reservoir after running if it was completely full. I know that it will bypass the gap it pressures get to high. I just didn't know if it was a normal part of the colony system or only when it's too high, too low. This bottle says "Can be added to overflow tank, but will take 4 to 5 heating and cooling cycles for product to fully enter system"Not in OP's example.
What's the backstory, does OP want to do a "gentle" coolant changeout? Fix a concentration issue to get back to 50/50? Working only with the overflow bottle is a dumb way to maybe eventually get there.
My three Chrysler vehicles all have a standard overflow. The two GM's use a surge tank with the cap on it.What Year Model car and engine?
I that was true on modern vehicles, you would not observe the reservoir level change from hot shutdown FULL - to cold start LOW"It depends."
If you are referring to an overflow tank, no. That is supposed to be a one way path, since the radiator cap only allows coolant to escape when the pressure exceeds the caps rating. If the cap has failed, then you will see some back and forth, but mostly overflowing.
If referring to an expansion tank, yes. It's part of the circulation.
^^ this"It depends."
If you are referring to an overflow tank, no. That is supposed to be a one way path, since the radiator cap only allows coolant to escape when the pressure exceeds the caps rating. If the cap has failed, then you will see some back and forth, but mostly overflowing.
If referring to an expansion tank, yes. It's part of the circulation.
No, not that. The cap is a two-way device. After the heated coolant expands into the overflow, it re-enters the radiator upon cooling. It’s also a return valve.^^ this
It depends. Some cars utilize a one way. Others have a two way.No, not that. The cap is a two-way device. After the heated coolant expands into the overflow, it re-enters the radiator upon cooling. It’s also a return valve.